De Bock K, Derave W, Eijnde B O, Hesselink M K, Koninckx E, Rose A J, Schrauwen P, Bonen A, Richter E A, Hespel P
Research Center for Exercise and Health, F.A.B.E.R. - K.U.Leuven, Tervuursevest 101, B-3001 Leuven Heverlee, Belgium.
J Appl Physiol (1985). 2008 Apr;104(4):1045-55. doi: 10.1152/japplphysiol.01195.2007. Epub 2008 Feb 14.
Skeletal muscle gene response to exercise depends on nutritional status during and after exercise, but it is unknown whether muscle adaptations to endurance training are affected by nutritional status during training sessions. Therefore, this study investigated the effect of an endurance training program (6 wk, 3 day/wk, 1-2 h, 75% of peak Vo(2)) in moderately active males. They trained in the fasted (F; n = 10) or carbohydrate-fed state (CHO; n = 10) while receiving a standardized diet [65 percent of total energy intake (En) from carbohydrates, 20%En fat, 15%En protein]. Before and after the training period, substrate use during a 2-h exercise bout was determined. During these experimental sessions, all subjects were in a fed condition and received extra carbohydrates (1 g.kg body wt(-1) .h(-1)). Peak Vo(2) (+7%), succinate dehydrogenase activity, GLUT4, and hexokinase II content were similarly increased between F and CHO. Fatty acid binding protein (FABPm) content increased significantly in F (P = 0.007). Intramyocellular triglyceride content (IMCL) remained unchanged in both groups. After training, pre-exercise glycogen content was higher in CHO (545 +/- 19 mmol/kg dry wt; P = 0.02), but not in F (434 +/- 32 mmol/kg dry wt; P = 0.23). For a given initial glycogen content, F blunted exercise-induced glycogen breakdown when compared with CHO (P = 0.04). Neither IMCL breakdown (P = 0.23) nor fat oxidation rates during exercise were altered by training. Thus short-term training elicits similar adaptations in peak Vo(2) whether carried out in the fasted or carbohydrate-fed state. Although there was a decrease in exercise-induced glycogen breakdown and an increase in proteins involved in fat handling after fasting training, fat oxidation during exercise with carbohydrate intake was not changed.
骨骼肌对运动的基因反应取决于运动期间及之后的营养状况，但肌肉对耐力训练的适应性是否受训练期间营养状况的影响尚不清楚。因此，本研究调查了耐力训练计划（6周，每周3天，1 - 2小时，峰值摄氧量的75%）对中度活跃男性的影响。他们在禁食（F组；n = 10）或碳水化合物喂养状态（CHO组；n = 10）下进行训练，同时接受标准化饮食[碳水化合物提供总能量摄入（En）的65%，脂肪提供20%En，蛋白质提供15%En]。在训练期前后，测定了2小时运动期间的底物利用情况。在这些实验期间，所有受试者均处于进食状态，并额外摄入碳水化合物（1 g·kg体重⁻¹·h⁻¹）。F组和CHO组的峰值摄氧量（增加7%）、琥珀酸脱氢酶活性、葡萄糖转运蛋白4（GLUT4）和己糖激酶II含量均有相似程度的增加。脂肪酸结合蛋白（FABPm）含量在F组显著增加（P = 0.007）。两组的肌内甘油三酯含量（IMCL）均保持不变。训练后，CHO组运动前糖原含量较高（545 ± 19 mmol/kg干重；P = 0.02），而F组则不然（434 ± 32 mmol/kg干重；P = 0.23）。对于给定的初始糖原含量，与CHO组相比，F组运动诱导的糖原分解减弱（P = 0.04）。训练对IMCL分解（P = 0.23）以及运动期间的脂肪氧化率均无影响。因此，无论在禁食还是碳水化合物喂养状态下进行短期训练，峰值摄氧量的适应性变化相似。尽管禁食训练后运动诱导的糖原分解减少，且参与脂肪代谢的蛋白质增加，但在摄入碳水化合物的运动过程中，脂肪氧化并未改变。
